Selective termination of stimulation to deliver post-stimulation therapeutic effect

Abstract

In some examples, electrical stimulation is delivered to a patient such that selective termination of the stimulation causes a therapeutic effect in the patient after termination of the electrical stimulation to the patient. The electrical stimulation may be insufficient to produce a desired therapeutic effect in the patient during stimulation, but sufficient to induce a post-stimulation desired therapeutic effect following termination of the stimulation. In some examples, the electrical stimulation may be sub-threshold electrical stimulation. In some examples, the desired therapeutic effect may alleviate bladder dysfunction, bowel dysfunction, or other disorders. The stimulation may be selectively terminated in response to one or more therapy trigger events to induce the post-stimulation therapeutic effect.

The invention claimed is: 
     
       1. A system comprising:
 a stimulation generator configured to generate and deliver electrical stimulation to a patient; and 
 processing circuitry configured to:
 control the stimulation generator to deliver the electrical stimulation to the patient; 
 detect a therapy trigger event; 
 responsive to detecting the therapy trigger event, control the stimulation generator to terminate the delivery of the electrical stimulation; 
 responsive to controlling termination of the delivery of the electrical stimulation, determine whether termination of the electrical stimulation induced a desired therapeutic effect in the patient, wherein the desired therapeutic effect comprises a decrease in bladder dysfunction; and 
 control the stimulation generator based on the determination of whether termination of the electrical stimulation induced the desired therapeutic effect in the patient. 
 
 
     
     
       2. The system of  claim 1 , wherein the processing circuitry is configured to:
 determine whether termination of the electrical stimulation induced the desired therapeutic effect in the patient by at least:
 determining that a physiological state of the patient changed after termination of the electrical stimulation; and 
 responsive to determining that the physiological state of the patient changed after termination of the electrical stimulation, determining that termination of the electrical stimulation induced the desired therapeutic effect in the patient; and 
 
 control the stimulation generator by, responsive to determining that termination of the electrical stimulation induced the desire therapeutic effect in the patient, controlling the stimulation generator to subsequently control the stimulation generator to deliver the electrical stimulation to the patient and controlling the stimulation generator to terminate the delivery of the electrical stimulation to induce the desired therapeutic effect in the patient. 
 
     
     
       3. The system of  claim 2 , wherein the processing circuitry is configured to determine that the physiological state of the patient changed after termination of the electrical stimulation by at least determining that a sensed value of a physiological parameter exceeds a threshold. 
     
     
       4. The system of  claim 2 , further comprising a sensor configured to sense a physiological parameter indicative of the physiological state. 
     
     
       5. The system of  claim 2 , wherein the physiological state comprises at least one of a bladder pressure, a bladder contraction frequency, a nerve activity, a muscle activity, a patient activity level, or a patient posture state. 
     
     
       6. The system of  claim 1 , wherein the electrical stimulation is a first electrical stimulation at least partially defined by a first set of stimulation parameter values, and wherein the processing circuitry is configured to:
 determine whether termination of the first electrical stimulation induced a desired therapeutic effect in the patient by at least determining that a physiological state of the patient did not change after termination of the first electrical stimulation, the physiological state not changing being indicative of the desired therapeutic effect not being induced by termination of the first electrical stimulation, and 
 control the stimulation generator by, responsive to determining that the physiological state of the patient did not change, selecting a second set of stimulation parameter values that at least partially defines a second electrical stimulation deliverable to the patient and is configured to induce the desired therapeutic effect in the patient after termination of delivery of the second electrical stimulation, the second set of stimulation parameter values being different than the first set of stimulation parameter values. 
 
     
     
       7. The system of  claim 6 , wherein the processing circuitry is configured to select the second set of stimulation parameter values based on a next therapy program in a list of ordered therapy programs stored in a memory. 
     
     
       8. The system of  claim 6 , wherein the processing circuitry is configured to select the second set of stimulation parameter values based on a lookup table that indicates one or more parameter values to try based on the physiological state determined after termination of the first electrical stimulation. 
     
     
       9. The system of  claim 1 , wherein the therapy trigger event comprises at least one of an expiration of a timer, a particular time of day, or a detected physiological state of the patient. 
     
     
       10. The system of  claim 1 , wherein the therapy trigger event comprises a request by a user for the desired therapeutic effect. 
     
     
       11. The system of  claim 1 , wherein the electrical stimulation comprises an intensity that is below an intensity of at least one of a therapeutic threshold or a physiological threshold of the patient. 
     
     
       12. The system of  claim 1 , wherein the desired therapeutic effect comprises at least one of a reduced bladder contraction frequency, a reduced urgency, or reduced incontinence. 
     
     
       13. A method comprising:
 controlling, by processing circuitry, a stimulation generator to generate and deliver electrical stimulation to a patient; 
 detecting, by the processing circuitry, a therapy trigger event; 
 responsive to detecting the therapy trigger event, controlling, by the processing circuitry, the stimulation generator to terminate the delivery of the electrical stimulation; 
 responsive to controlling termination of the delivery of the electrical stimulation, determining, by the processing circuitry, whether the termination of the electrical stimulation induced a desired therapeutic effect in the patient, wherein the desired therapeutic effect comprises a decrease in bladder dysfunction; and 
 controlling, by the processing circuitry, the stimulation generator based on the determination of whether termination of the electrical stimulation induced the desired therapeutic effect in the patient. 
 
     
     
       14. The method of  claim 13 , wherein:
 determining whether the termination of the electrical stimulation induced the desired therapeutic effect in the patient comprises:
 determining that a physiological state of the patient changed after termination of the electrical stimulation; and 
 responsive to determining that the physiological state of the patient changed after termination of the electrical stimulation, determining that termination of the electrical stimulation induced the desired therapeutic effect in the patient; and 
 
 controlling the stimulation generator comprises, responsive to determining that termination of the electrical stimulation induced the desire therapeutic effect in the patient, controlling the stimulation generator to subsequently control the stimulation generator to deliver the electrical stimulation to the patient and controlling the stimulation generator to terminate the delivery of the electrical stimulation to induce the desired therapeutic effect in the patient. 
 
     
     
       15. The method of  claim 14 , wherein determining that the physiological state of the patient changed after termination of the electrical stimulation comprises determining that a sensed value of a physiological parameter exceeds a threshold. 
     
     
       16. The method of  claim 14 , further comprising sensing a physiological parameter indicative of the physiological state. 
     
     
       17. The method of  claim 13 , wherein the electrical stimulation is a first electrical stimulation at least partially defined by a first set of stimulation parameter values, and wherein determining whether the termination of the electrical stimulation induced a desired therapeutic effect in the patient comprises:
 determining whether termination of the first electrical stimulation induced a desired therapeutic effect in the patient comprises determining that a physiological state of the patient did not change after termination of the first electrical stimulation, the physiological state not changing being indicative of the desired therapeutic effect not being induced by termination of the first electrical stimulation; and 
 controlling the stimulation generator comprises, responsive to determining that the physiological state of the patient did not change, selecting a second set of stimulation parameter values that at least partially defines a second electrical stimulation deliverable to the patient and is configured to induce the desired therapeutic effect in the patient after termination of delivery of the second electrical stimulation, the second set of stimulation parameter values being different than the first set of stimulation parameter values. 
 
     
     
       18. The method of  claim 17 , wherein selecting the second set of stimulation parameter values comprises selecting the second set of stimulation parameter values based on a next therapy program in a list of ordered therapy programs stored in a memory. 
     
     
       19. The method of  claim 17 , wherein selecting the second set of stimulation parameters comprises selecting the second set of stimulation parameters based on a lookup table that indicates one or more parameters to try based on the physiological state determined after termination of the first electrical stimulation. 
     
     
       20. The method of  claim 13 , wherein the therapy trigger event comprises at least one of an expiration of a timer, a particular time of day, or a detected physiological state of the patient. 
     
     
       21. The method of  claim 13 , wherein the therapy trigger event comprises a request by a user for the desired therapeutic effect. 
     
     
       22. The method of  claim 13 , wherein the electrical stimulation comprises an intensity that is below an intensity of at least one of a therapeutic threshold or a physiological threshold of the patient. 
     
     
       23. The method of  claim 13 , wherein the desired therapeutic effect comprises at least one of a reduced bladder contraction frequency, a reduced urgency, or reduced incontinence. 
     
     
       24. A system comprising:
 means for delivering electrical stimulation to a patient; 
 means for detecting a therapy trigger event; 
 means for, responsive to detecting the therapy trigger event, controlling the means for delivering electrical stimulation to terminate the delivery of the electrical stimulation; 
 means for, responsive to controlling termination of the delivery of the electrical stimulation, determining whether the termination of the electrical stimulation induced a desired therapeutic effect in the patient, wherein the desired therapeutic effect comprises a decrease in bladder dysfunction; and 
 means for controlling the means for delivering electrical stimulation based on the determination of whether termination of the electrical stimulation induced the desired therapeutic effect in the patient.